Refrigerative system



Aug. l1, 1936. Jy E, DUBE' REFRIGERATIVE SYSTEM Filed Aug. 18, 1953 INVENTOR, 7d/WY 5.!7055,

ATTORNEY.

?aiented Aug. il, i936 REFRIGERA a SYSTEM John E. Bube, Chicago, Bl. I Application August 18, i933, Serial No. 685,733

4 Claims.

The invention relates to refrigerative systems of the type wherein a liquid having a low boiling point, is vaporized and condensed; and, said invention, in its broadest aspect, involves two cooperating circuits, one of which contains the refrigerating liquid, and the other of 4which contains a motive liquid.

Said invention also involves details of construction which facilitate the operations of these two circuits, as well as the operation of the entire system.

The invention will best be understood if reference be had to the accompanying drawing in which- Figure 1 shows one embodiment of the invention in elevation, parts of the apparatus being broken away to reveal details of construction, and

Figure 2 is a horizontal sectional view showing a modified detail of the apparatus.

' The apparatus, as illustrated in said drawing, is provided with a separator tank I which contains two liquids 2, 3, the liquid 2 being the refrigerating liquid, and the liquid 3 being the motive liquid.

These two liquids should have different specie gravities in order that their stratification and separation in said separator tank, may adequately be eiected, although, if found desirable, the stratication thereof may be aided by centrifugal force developed in any well-known manner. However, since any two liquids that may be employed will, before reaching the separation tank, be thoroughly blended, and since time is required for their separation, there will exist a zone intermediate the zones 2. 3, and indicated by'the numeral 4, wherein the two liquids will always be mixed, although, in said zones 2, 3, they will be substantially, if not entirely, separated.

It is, of course, preferable to select liquids which are, notonly chemically stable as respects each other, but readily separable. The motive liquid 3 must be less volatile than the refrigerating liquid 2, and it may be water or oil, while said refrigerating liquid may be a known volatile hydrocarbon, or sulphur dioxide.

Leading from a point within and below the upper end of the tank I is a pipe 3 that is provided with any well-known pressure-regulating valve 6 for controlling the out-flow of the refrigerating liquid 2. This pipe communicates with the evaporator coil l, and said coil leads to an injector which comprises a casing 8 having ends 9, I0 that respectively carry a contracted nozzle II and a Venturi-tube I2.

Said nozzle II is supplied with motive liquid owing through an air-cooled coil I3 which leads from the lower end of the supply tank I to a rotary pump I 4 that communicates with said nozzle, and the Venturi-tube I2 discharges into a tube I5 which carries the motive liquid mixed with condensed vapor into the tank I.

Motive liquid cooled in coil I3 is forced by pump I4 through ejector 8 sucking out the refrigerant vapor from the coil 'I and compressing said refrigerant vapor. Said refrigerant vapor, though cooler than the high velocity liquid motive fluid before compression, is raised to a higher temperature than the motive fluid, that is, to a temperature which corresponds to the pressure after compression, so that heat is transferred from the high-temperature compressed refrigerant to the liquid motive iiuid, causing the vaporized refrigerant to condense. 'I'hereupon separation of the refrigerant from the motive uid takes place in tank I. The motive fluid then passes the coil I3 to repeat the cycle, and the refrigerant liquid passes through the regulating valve 6 to the refrigerating coil l.

The rotary pump I4 is driven by an electrical motor I 6 of usual construction, and the operation of said motor is controlled by a well-known thermostatic switch mechanism I'I, I8, I9, 2li,`

2|, the expansive element I'I of which is subjected to the heat of the evaporator coil l.

In the modification shown in Figure 2', the pipe I5 enters the tank I at a tangent to its circumference, to thereby enable the inflowing blended liquids to impart a. whirling motion to the contents of said tank, and aid the stratification and separation of said liquids by the aforesaid centrifugal action.

The several parts of the apparatus, hereinbe- Iore described, excepting the pump and its stuifing box and the motor and its controlling mechanisms, are connected by fixed vapor-tight joints Which prevent loss of the refrigerant and the motive liquid by leakage. Should any of the motive liquid escape through said stuiiing box, the loss will be compensated for by the expansion of the body of vapor in the zone 22 of the tank I.

Thus far it has been assumed that the motive liquid is heavier than the refrigerating liquid, but if the reverse were the case, the refrigerating liquid would be disposed at the bottom of the tank I, and an obvious rearrangement of the circuits would be required.

When the apparatus is to be operated, the

tank I is partially filled with the motive liquid 3, and upon this liquid is floated the liquid refrigerant 2. When saidtank is thus charged, the pressure therein will be P, this being the pressure of the refrigerant at the temperature T.

The liquid refrigerant flowing through said pipe 5, passes into and actuates the pressureregulating valve 6, and this valve is so adjusted as to maintain, in the evaporating coil 1, a low pressure p corresponding with the desired low temperature t. The liquid refrigerant, as it ows into the evaporating coil, expands into vapor, and draws the heat required for its vaporization from the medium surrounding said vaporizing coil.

The vaporous refrigerant, leaving the evaporator coil 1, enters the injector in which it is mixed with and condensed by the jet of motive liquid flowing from the nozzle II. The pump I4 forces motive liquid, cooled in the coiled heat exchanger I3, into and through said nozzle, and since the temperature thereof has been reduced from T to T1, the quantity of heat removed therefrom will be equal to the quantity of heat taken from the medium surrounding the evaporator coil 1.

Said heat exchanger I3 may be air cooled, as shown, or it may be enclosed in a water tower. The kind of cooling apparatus employed will, of course, be determined by the required capacity thereof, by the desired differentials of temperature in the circuits of the system, and by the temperatures of the available cooling mediums.

The intake pressure of the pump I4, theoreti cally will be equal to the vapor pressure P in the tank l, although, because of the frictionai resistances in the coil I3, it will be less than P. Sufiicient energy therefore must be vapplied to the pump I4, to enable it to raise the pressure of the motive liquid from P yto P1, or to a. pressure that is high enough to effectuate the work performed by the Ajet issuing from the nozzle II, and also to overcome the frictional resistances of the system.

The jet emanating from the nozzle I i, will entrain the vaporous refrigerant and carry it through the Venturi-tube wherein it is condensed.

This condensation will take place even though the motive liquid has a higher temperature than the vaporous refrigerant, since said condensation is produced by compression. The compression also reduces the volume of the refrigerant and produces a suction which enhances the efficiency of the jet.

4It is of the greatest importance that the vapor pressure of the motive liquid, at temperature T, shall be less than the vapor pressure of the refrigerant at temperature t, namely, thepressure p. If this were not so, the motive liquid. upon attaining a velocity high enough to reduce itsl static pressure -belowp, would vaporlze and render the jet impotent.

0n account of the condensation of the vaporous refrigerant in the jet of motive liquid, the temperature oi that liquid in said jet, is raised from temperature T1 to temperature T. so that a stream of mixed motive liquid and liquid refrigerant, at pressure P and temperature T, will enter the tank I through the pipe I5.

- The system, as above stated, is controlled by the automatic switch mechanism herein described. This mechanism starts the motor I4 whenever the temperature of the medium being cooled rises above a pre-.determined limit, and stops said motor when the temperature of that medium is sufficiently low.

The injector, instead of having a single nozzle, may be one of the multiple-nozzle type.

Having thus described my invention, what I claim is:Y

1. A refrigerative system, including at least two circuits respectively containing liquids having different boiling points and diiferent speciiic gravities, said two circuits having a passage which is common to both of them and is provided with an injector in which the vapor of. the refrigerating liquid is condensed by the motive liquid.

2. A refrigerating system including a refrigerant circuit and a motive uid circuit, said re, frigerant circuit comprising a separator, an expansion valve, an evaporator coil, and an ejector, in the order named, said motive fluid circuit comprising said separator, a cooling coil, a pump, and said ejector, in the order named, said cooling coil functioning to drop the temperature of the motive uid before it reaches the ejector, so that as the ejector compresses the refrigerant sucked out of the evaporator, it condenses it.

3. The appartus as in claim 2, further characterized in that it includes an electric circuit have therein two liquids of dineren?, specific gravities and boiling points.

50ml E. D. 

